Ad astra per aspera

Tuesday, 29 September 2015

Water is
essential to life as we know it here on Earth. The presence of liquid water on
Mars today has implications for geology, hydrology, the study of the origins
and distribution of life in our solar system and beyond, and also for human
space exploration.

While the
average temperature on Mars is less than -50 degrees Celsius, temperatures of
up to 27 degrees Celsius can occur during warm seasons. On certain slopes of
terrain, narrow streaks have been observed to appear and grow during these warm
periods. A solution of salts in water can lower the freezing point of water by
up to 80 degrees Celsius, thereby significantly lowering the evaporation rate
of water, and thus increasing the possibility of forming and stabilising liquid
water on the surface of present-day Mars.

Brine- a
solution of salt in water- has therefore been proposed to explain these
streaks, however, no evidence of water or such salts has yet been found. Now,
spectral data from the Mars Reconnaisance Orbiter (MRO) has found hydrated salts
at all four locations where streaks were observed on the surface of Mars,
probably magnesium perchlorate, magnesium chlorate and sodium perchlorate.

These
findings strongly suggest that seasonal warm slopes are currently forming
liquid water on Mars. While the possible origins of this water are not yet
understood, a variety of formation mechanisms in different locations on the
planet may be taking place. With respect to the search for microbial life on
Mars, this discovery means we will be working hard to further characterise and
explore these unique regions of Mars.

While it is
good news for planned human settlements on Mars that there may be liquid water
present, COSPAR and the Outer Space Treaty aim to protect
extra-terrestrial bodies to make future science investigations possible, and in
particular to prevent contamination by Earth life of unique areas where extra
terrestrial life may exist. So it is likely that these areas where liquid water
may be flowing will be out of bounds for human settlement until careful and detailed
astrobiological investigations have been made in these areas.

But excitingly, as a result of investigating these
unique locations supporting liquid water on Mars, in the next few years we
could make one of the most profound discoveries in the history of life on Earth-
the discovery of life on another planet.

Monday, 21 September 2015

I find myself living at a very particular point in the
almost 4 billion years of the evolution of life on this planet. I feel lucky,
no extraordinarily privileged, to be alive right now, when for the very first
time, we are able to investigate terrestrial life on scales smaller than the
size of atoms, as well as look to the skies for evidence of extra-terrestrial
life many hundreds of light years beyond Earth.

This beauty, this complexity, this body of knowledge that we
are creating as humans flies in the face of the second law of thermodynamics, which
describes how things tend to become more rather than less disordered as
time goes on.

In spite of being participants in this physically unlikely
era of human information creation, I believe we are often not open to seeing
the bigger picture. Perhaps because in this age of information inundation, we feel
more comfortable forgetting how much we still don’t know…

I want to be the most improbable human that I can be. I am
prepared to give up my life on Earth for the unprecedented contribution I would
be able to make to the sum of human knowledge from a new world. I would like to
become one of the first citizens of Mars, and today I would like to talk about
why.

Quantum mechanics is our most fundamental theory of
reality- a description of phenomena occurring in systems on scales ­millions of
times smaller than the resolution of the human eye, consisting of objects such
as photons, electrons and atoms. To get an idea of just how small…

Micrometer-sized objects, like an individual human hair are
visible to the naked eye. A thousand times smaller than that is the width of
the DNA molecule, just a few nanometers, the helical structure of which was
first observed only in 1952 using an x-ray imaging technique. And atoms are another
ten times smaller than that, best observed with a microscope that uses a beam
of electrons for imaging.

Quantum biology: You may wonder what connection these
fields may have- biological objects like elephants are things that we can see,
while quantum theory deals with objects that are far smaller that the
resolution of the eye. However, the idea that quantum mechanics may play a role
in living systems is by no means a new idea.

On this very day, the 15 August, in 1932, quantum physicist
Niels Bohr delivered a lecture “Light and Life” at the International Congress
on Light Therapy in Copenhagen, raising the question of whether quantum theory
could contribute to a scientific understanding of living systems. In attendance
was an intrigued Max Delbruck, a young physicist who later contributed to the
establishment of the field of molecular biology. Both of these brilliant
scientists won Nobel Prizes for their contribution to our understanding of
reality.

The most developed area of quantum biology is the study of
the very early stages of photosynthesis- up to less than the first billionth of
a second. Only recent developments in an experimental technique called
ultrafast spectroscopy have enabled us to image processes that happen on such
quick timescales. This very early part of photosynthesis is almost perfectly
efficient and we would like to understand how Nature does it so well. It turns
out we have to use quantum physics to do so.

Understanding photon by photon, molecule by molecule how
photosynthesis works, is a necessary step towards designing and engineering
biologically inspired artificial photosynthetic solar cells, with the ability
to harness sunlight energy with greater efficiency than is possible with
currently existing technology. Quantum biology promises to contribute to the
kinds of green renewable energy technologies essential for our continued
existence on this planet (and possibly others…)

But in my opinion the greatest possible contribution of the
field of quantum biology would be to help us in some way to answer the question
that we have asking since time immemorial: What is life? What distinguishes
a living system from the matter of which it is made, and how did it come about?
While we are instinctively good at telling the difference between a living
creature and bunch of inanimate molecules, a precise scientific theory of what
distinguishes the two, and how life emerges in the first place from these
molecules is something we are still working on. I think it’s funny that this
ethanol molecule looks kind of similar to this horse, but I don’t think this is
a clue…

I think the fact that we have identified quantum aspects of
photosynthesis, one of the earliest living processes to have emerged on Earth,
suggests that going down to these tiny scales may help us understand how life
emerged in the first place.

What would be really helpful in the quest to understand the
fundamental principles underlying the emergence of life would be to find just
one other example of the phenomenon… We have not yet discovered any other
location where life exists and all organisms on Earth appear to have evolved
from a common ancestor.

Astrobiology is the study of the
origin, evolution, distribution, and future of life in the universe. And the
universe is a big place- we measure it in the distances that light travels in a
given time, light being the fastest thing that we know of in our current
understanding (with a speed of almost 300 000 km/s ). While Mars is just a few
light minutes away, light takes around four years to travel to the nearest
star, over a thousand to travel to that intriguing recently discovered Earth-like
planet called Kepler-452b, millions of years to reach the nearest galaxy
Andromeda, and nearly 50 billion years to reach the furthest edge of the
observable universe.

There is a theory with a crazy name, panspermia,
which says that life on the Earth originated when the chemical
precursors of life present in outer space reached this suitable environment.
The theory is not so crazy when you consider that many meteorites found on
Earth contain a range of building blocks of life- for example over 70 different
amino acids have been detected in the Murchison meteorite that fell in
Australia in 1969. Furthermore, we think
that quantum mechanics may provide the tools to understanding how these
precursors of life emerged in space…

If you’re feeling mentally taxed, you
should be, I’ve taken you on a journey from the tiny scales where atoms exist,
out to the furthest edge of the universe many billions of light years away, on
the quest to understanding life. That’s a big picture! And a picture I spend a
lot of time inside as a researcher in the field of quantum biology and more
recently in a field I would like to call quantum astrobiology.

The point I want to make is that so far
as we can tell, what we are doing here on Earth as living systems and in
particular as humans, is very improbable. In a vast universe, so far, we
represent the only instance that we know of, where collections of molecules,
because that’s what we are, have observed reality, made sense of it through language,
and finally found ways to record and communicate this information, which has
culminated in the Internet, in my opinion, one of our finest moments. This is
an unlikely time and place in the universe in which we find ourselves!

What I find perplexing is that in
spite of living in this improbable era of human existence, and even in spite of,
for many of us, having the sum of human knowledge at our fingertips, rather
than rejoicing in the hugeness of the picture we have of reality, and in the
spirit of exploration and discovery of the vastness of what still remains
unknown, many people are overwhelmed, unnerved and indeed find it incomprehensible
that I want to move to Mars, on a way-way trip. Although some people may have
an idea of who they would like to send on such a trip…

Billions
of years of evolution of life on Earth have culminated in the possibility of us
calling another planet home for the very first time. Untold discoveries lie in wait, including the
possiblity of finding evidence of life there, which would be a giant leap in
terms of understanding who are we, where we come from and where we are going. I
have applied and been short-listed along with 99 others from around the planet with
the Mars One Project, to go and live on Mars because I would be prepared to
sacrifice a lot for this idea, this adventure, this achievement, that would not
be my own, but that of all humanity. Even returning to Earth.

What I would like to point out immediately is that we are
all survivors of one-way trips, wherever on the surface of the Earth we happen
to currently live. According to the fossil record, homo sapiens emerged in
central eastern Africa around 200 000 years ago, and we have been exploring the
surface of the Earth ever since. My ancestors made the hazardous 5 month trip
from Europe to the Southern tip of Africa in 1688 without any intention or means
of return- I am the 11th generation of descendants of Huguenot
refugees from France, now proudly South African. And 500 years from now there
may well be human Martians telling tales of the perilous one-way journey their
ancestors made in the early 21st century from Earth.

All the observations we have made and information we have
gathered is the result of having explored the unknown. The technologies that
many of us consider so indispensible in our daily lives are often the
unexpected result of investigating something new. I like to think of the
invention of the heat engine as the eventual technological solution to the bad
weather the first African explorers encountered on discovering Europe.

In the same way I hope that the relatively hostile environment
on Mars will lead to new technologies that can help us on Earth- to tackle
climate change, poor resource management and the poverty in which so many of us
live. Life on Mars will be a precious and fragile resource, and I believe that
an attitude of deep appreciation for life and all that is needed to sustain it
will charactise morality on Mars, and also, I hope, influence the way people think
on Earth.

This is what we have always done as humans and what we will
continue to do- we observe, we dream and we expand our horizons through the
realisation of these dreams. I want to make the best contribution of which I am
capable to this grand and improbable era of human information creation.I want to be one of the first conscious minds to know what it is like to
live in a totally new world. I want to add to the sum of human
knowledge by contributing to the establishment, and possibly the discovery of
evidence of, life on Mars.

To conclude, I feel privileged to be living at a time when
the opportunity to expand our imaginations and our world further than ever
before, is within reach. Why I want to go to Mars is simple: to me the allure
of the unknown has always felt far more powerful than the comfort of the known.A presentation of these ideas at TEDx Cape Town https://www.youtube.com/watch?v=6MryDEd7CE0

Monday, 9 June 2014

Can
quantum biology help us to understand what distinguishes a bunch of
molecules from a living organism?

In
the beginning, during the first billion years (Gyr) after the Earth
was formed about 4.5 Gyr ago, intense meteor bombardment left little
remains of the original crustal rocks. High energy collisions with
meteorites up to 500 km in diameter periodically disintegrated newly
formed continental crust and vapourised early oceans, annihilating
primitive life forms possibly existing near the surface.

Gene
sequencing suggests that the most primitive known domains of life,
namely bacteria and archaea, have been evolving separately for as
long as 4 Gyr. Deep-sea volcanic vents are candidates for supporting
such early life. The oldest fossils of single-celled microbes are
dated at around 3.5 Gyr, while the oldest evidence of the more
complex multicellular precursors of plants and animals is more
recent, at around 2 Gyr. Structurally, it appears that this
complexity in fact arose as the happy endosymbiotic result of the
invasion of the archaean cell by bacteria!

In
the meantime, life has become so prolific and so complex that human
life forms have taken up the study of life and its origins. But are
we any closer to an answer? Can we state exactly what it is that
distinguishes a bunch of molecules from a living organism?

An
intriguing experiment by Miller and Urey in 1953 showed that
electrical activity in a gaseous mixture of methane, ammonia, water
and hydrogen can produce amino acids: the building blocks of
proteins. In spite of more recent and remarkable work in viable DNA
design, no experiment has yet been able to synthesise from basic
components an object that has the characteristics of a living cell.

All
living systems are made up of molecules, and the properties of
molecules are given by quantum mechanics, our most successful and
fundamental theory to date. Living systems are necessarily open
systems constantly exchanging energy and matter with the environment
in order to maintain the non-equilibrium state synonymous with
living. While living systems are therefore fundamentally open quantum
systems, the level of complexity typical of biological systems poses
a huge computational challenge to such a fundamental description.
Furthermore, many of the processes associated with life are
sufficiently described by Newtonian physics.

Quantum
biology is the applied science of open quantum systems to those
aspects of biology where a description in terms of Newtonian physics
is insufficient. An important question is whether quantum theory can
add anything to biology: We know that molecules are ultimately
described by quantum chemistry, but can such a description help us to
understand life itself?

The
most well-established area in quantum biology is the study of aspects
of one of life's oldest processes: photosynthesis. While evidence of
quantum mechanical tunneling in electron transfer in purple bacteria
was first reported almost half a century ago, more recently the
detection of quantum coherence in energy transfer in green sulphur
bacteria and marine algae has contributed to a revival of interest in
the possibility that the optimality of some biological processes is
due to a sustenance of quantum effects in the warm, wet and noisy
environments typical of living systems.

As
theorists, we are working hard to keep up. Our research in Durban,
with collaborators in Singapore and Amsterdam, has involved the
application of open quantum systems models of energy transfer to the
photosynthetic process, showing how interaction with an environment
can in fact enhance transport efficiency. More recently, we have
proposed that quantum
spin plays a direct role in reducing the
yield of potentially destructive states
during charge transfer in photosynthesis, constituting a new example
of a quantum mechanical protective mechanism in a living organism.

Given
that the simplest living systems exhibit functional complexity of a
quantum nature when probed at the limits of our instrumentation, that
far more complex animals are able to sense subtle changes in their
environments with an accuracy described by quantum mechanics, should
come as no surprise. The proposal that navigation in the Earth's
magnetic field, as well as our senses of vision and smell, and also
our cognition, require quantum mechanical description, are exciting
developing areas of quantum biology.

The
highest achievement of quantum biology would be a contribution to a
scientific understanding of what distinguishes a living system from
the inanimate matter from which it is constructed, i.e. a theory of
life. The test of such a theory would be the synthesis of life
itself. In the absence of such a theory and its confirmation, outside
of famous works of fiction, quantum biology will, for now, have to
fulfill a more practical role.

The
primary importance of the field of quantum biology, in its present
state, lies in the identification and mimicry of the ingenious feats
of engineering taking place in systems ranging from bacteria to
birds. If non-trivial quantum effects on a macroscopic scale play a
role in getting the job done better in certain processes perfected
over billions of years at physiological temperatures and in immensely
complex systems, then there exists before our very eyes a wealth of
information in the biological world from which to draw inspiration
for our own technologies.

Synthetic
biology is gathering momentum to become the next big thing in
science, with biologically-inspired quantum artificial photosynthetic
systems
promising to contribute to the development of the kind of renewable
energy technologies essential for our continued existence on this
planet (and perhaps others!),
and this is just the beginning.

As
far as understanding what life is, however, we are limited by a lack
of precise knowledge of the conditions under which life emerged on
Earth, in a possibly singular event. Barring the sudden discovery of
evidence of life on Mars by the Curiosity rover or a roving Mars One
colonist, for now, we will have to be satisfied with a definition of
life as the continual state of change preceding death, and with the
knowledge that the rabbit hole goes as least as deep as we are
prepared to venture.

About Me

I'm writing this blog because of the fascinating discussion evoked by Mars One's plan to establish a permanent human settlement on Mars in 2026. I am currently one of 100 candidates to become the first residents. Follow me on Twitter @adrianamarais